Free Unlimited 4G Data Until 6/14. Mint Mobile is offering Up to 66% off on 3-Months of 4G LTE Data + unlimited Talk & Text Sim Kits for only $45.00 Free Shipping with Code: "IRFREESHIP" (Exp Soon). Afterward, plan will renew at the regular rate per month, which is still an incredible deal. This prepaid service uses T-Mobile's network towers but is substantially cheaper than using T-Mobile.